1. Field of the Invention
The present invention relates to an apparatus for inspecting an allergic reaction which is to show a degree of the reaction, particularly in a patch test for checking the presence or absence of a skin allergic reaction before treatment or surgery, etc., to an apparatus which can show the degree of the reaction with a numerical value.
2. Prior Art
There are some cases to cause an allergic reaction to skin by a substance which usually contacts with the skin such as cosmetics, fibers, metals, etc., and itching or inflammation sometimes remains on the skin. These reactions vary depending on individuals and can be generally expected by an inspection so-called a patch test. This test is carried out by adhering to skin a patch in which a solution which causes a certain allergic reaction with the skin is soaked at a fiber layer placed at the center portion of a thin adhesive sheet, peeling the patch after 1 or 2 days from adhesion and evaluating the presence or absence of, or the degree of flare with naked eyes.
The above judging method has now been widely spread but the judgment is carried out with naked eyes, so that the judgment is fluctuated by individuals and is a less objectivity. Also, in colored peoples, judgment becomes difficult as a density of melanin dye contained in the skin becomes high. Accordingly, it has been demanded to develop any quantitative measurement means with regard to the degree of flare, but at present, any effective means has neither been proposed nor practically been developed.
Generally speaking, flare or itching designates that an inflammation occurs at the portion and it can be considered to be a high bloodstream rate at the portion. Accordingly, if a means to measure how much is a bloodstream rate at the center portion of the flare portion higher than a peripheral portion of the flare portion is found out, it can be realized to quantification of a skin allergic reaction.
There are various means to measure a skin bloodstream, and the most frequently used is a method of using a laser Doppler blood-flowmetry. This method is carried out by preparing a pair of optical fibers, and laser light is irradiated to skin from one of the optical fibers. Then, reflected and scattered light is received by the other optical fiber to measure a Doppler shift frequency generated by movement of blood cells. In this method, however, a bloodstream value at one point alone can be measured, so that to measure the state of the patient, it is necessary to carry out the measurement of the bloodstream at several points by moving the probe and an average value thereof is to be calculated. Moreover, it is difficult to properly evaluate an increased percentage of the bloodstream.
The inventor has invented a monitoring system of a bloodstream distribution called “laser speckle flowgraphy” (hereinafter abbreviated to as “LSFG”) due to image analyses of laser scattered light in U.S. Pat. No. 4,862,894 whole contents of which are incorporated herein by reference, which relates to an apparatus for monitoring a bloodstream and put into practice in the field of ophthalmology. This method is to irradiate broadened laser beam to living tissue such as the retina and skin, detect a granular pattern (which is laser speckle) with an image sensor placed on an image plane, and then, display the results as a map state by calculating a rate of time variation of speckles at the respective image elements. According to this system, bloodstream map for a wide area of the surface layer of a living body can be shown as an image with a measurement.
It is possible to carry out an evaluation of the patch test using the LSFG apparatus, but there are some problems. First, in the LSFG system, bloodstream values measured are values shown only by an arbitrary unit having no dimension. Thus, a user usually wishes to know actual values (mm/sec) of the bloodstream velocity at the measured portion and likely say a complaint about the fact that the actual values are unknown.
In an actual LSFG apparatus presently used, there is neither function to obtain a value of bloodstream as a ratio based on a certain point as a standard nor function to show the results as a two-dimensional map or a graph.
There is also no function in the actual LSFG apparatus presently used to obtain an increased value of bloodstream at a tested portion by a patch test in a percentage relative to the portion other than the tested portion, and to display the results with single numerical value.
Moreover, when an allergen of a person to be tested is to be specified among a material which contains a large number of components such as a cosmetic, etc., it cannot help estimating the allergen(s) from the data of the patch test with naked eyes. However, it is extremely difficult to estimate the degree of the allergic reaction with higher precision by the above-mentioned evaluation method of several degrees such as +, ++, etc. Thus, one wishes to develop a sole use system for the patch test, there are some points to be improved in the actually using LSFG system.
In the actual patch test, a circular fiber layer into which a solution to be tested is impregnated is adhered to a skin of a person to be tested, peeled off after lapse of a certain period of time and judged whether flare appears or not at the portion of the patch to which the test solution is impregnated with naked eyes. In such a case, it is a main object to investigate whether the bloodstream at the flare portion is increased with a certain degree as compared to the peripheral portions, and absolute values of the bloodstream rates are not considered. Only when the bloodstream values at the peripheral portion of the portion to be tested are measured as a standard, and relative values at the respective points based on the standard value are obtained and shown in a map state, required information can be obtained.
Moreover, by obtaining simple numerical values in which whether how many percentages the average bloodstream values at the circular region at which the patch test is carried out and the allergic reaction occurred are increased as compared to those at the peripheral portion, objective data substitute for judgment with naked eyes can be provided, so that it can be avoided to make a wrong diagnosis, etc.
According to judgment with naked eyes, if it is a two-step evaluation such as + and ++, it can be easily judged, but if it is an intermediate value, only a person skilled in the art can be judged. As compared with this judgment, by a method of detecting the bloodstream with a degree of percentages, precision with two-digit can be easily obtained and the test results of the bloodstreams can be obtained by the same numerical values irrespective of a person to be inspected. Moreover, a slight change whether how many percentages the portion to be inspected are increased as compared to the data measured yesterday can be easily checked when the previous data measured before is input in a computer.
Furthermore, if a color of the skin of a person to whom the patch test for checking an allergen(s) is carried out is dark or black, the results of the patch test can be hardly judged with naked eyes. However, when the measured bloodstream values at the portion in which the patch test had been carried out can be shown with numerical values, the results of the patch test can be easily obtained irrespective of the color of the skin and the allergen(s) can be easily specified.